SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    2515, 2520, 2505, 2511, 2508, 2512, 2523, 
    2525, 2517, 2507, 2528, 2530
  )

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "3.04"
    },
    "table": {
      "table_name": "cscart_categories",
      "access_type": "range",
      "possible_keys": [
        "parent",
        "idx_categories_parent_status"
      ],
      "key": "parent",
      "used_key_parts": [
        "parent_id"
      ],
      "key_length": "3",
      "rows_examined_per_scan": 12,
      "rows_produced_per_join": 12,
      "filtered": "100.00",
      "using_index": true,
      "cost_info": {
        "read_cost": "1.84",
        "eval_cost": "1.20",
        "prefix_cost": "3.04",
        "data_read_per_join": "33K"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ],
      "attached_condition": "(`cscart_db`.`cscart_categories`.`parent_id` in (2515,2520,2505,2511,2508,2512,2523,2525,2517,2507,2528,2530))"
    }
  }
}